CN101143707A - A kind of ultra-high frequency nano-oscillator - Google Patents

Abstract

An ultra-high-frequency nano-oscillator, belonging to a nano-oscillator, the oscillator is fixedly connected to the positive pole of a power supply by a fixed end of a carbon nanotube (1), and the free end of the carbon nanotube (1) is close to the negative electrode connected to the negative pole of the power supply (3 ), the gap is within 10% of the carbon nanotube length. When a voltage is applied between the positive and negative electrodes, a strong electric field is generated between the free end of the carbon nanotube and the negative electrode to cause the electrical elongation of the carbon nanotube, which can reach 10%, and the gap between the carbon nanotube and the negative electrode is reduced. until a tunneling current is generated. At this time, the electric field strength between them disappears due to the conduction of the current, the carbon nanotubes retract under the action of elastic strain energy, the distance between them and the negative electrode increases, the tunneling current disappears, the electric field increases accordingly, and the carbon nanotubes are electrically induced again. elongation. Carbon nanotubes alternately experience electrical elongation and elastic contraction, and the frequency increases with the decrease of carbon nanotube length, and can reach hundreds of GHz to several THz in the nanoscale length range. The structure is simple, and THz controllable oscillation can be realized.

Description

A kind of ultra-high frequency nano-oscillator

technical field

The invention relates to an ultra-high-frequency nano-oscillator designed at the nanometer scale based on the high-frequency oscillation characteristics of carbon nanotubes, the principle of electro-induced deformation, and the high sensitivity of tunneling current to the gap change caused by the tiny axial oscillation of carbon nanotubes .

Background technique

In the past ten years, carbon nanotube preparation technology has been highly developed. Due to the size characteristics and excellent mechanical and electronic properties of carbon nanotubes, researchers have designed numerous nanodevices based on carbon nanotubes, such as atomic force microscope probes, field emission flat panel displays, GHz mechanical oscillators, GHz switches, and bistable states. memory etc. Applicants have discovered an axial giant electrostrictive effect of carbon nanotubes up to about 10%. Based on the axial electro-deformation of carbon nanotubes in the electric field, its ultra-high axial oscillation eigenfrequency characteristics and quantum tunneling effect, the present invention designs a nano-device with controllable operating frequency and up to THz: high frequency nano-oscillator.

Contents of the invention

The purpose of the present invention is to provide a controllable ultra-high frequency nano oscillator with simple structure by utilizing the special electro-deformation ability of carbon nanotubes. The ultra-high-frequency nano-oscillator of the invention includes carbon nanotubes, positive electrodes, negative electrodes and a power supply. Wherein the fixed end of the carbon nanotube is connected to the positive electrode, there is a nanoscale gap between the free end of the carbon nanotube and the negative electrode, the positive pole of the power supply is connected to the positive electrode, and the negative pole of the power supply is connected to the negative electrode. The nanoscale gap between the free end of the carbon nanotube and the negative electrode is controlled within 10% of the length of the carbon nanotube, and its magnitude is related to the frequency requirement and the designed operating voltage. An array type ultra-high frequency nano-oscillator is an array structure in which carbon nanotubes are arranged in a row, and the fixed end of each carbon nanotube arranged in a row is fixed on the same positive electrode plate, connected to the positive electrode of the power supply, A nanoscale gap is maintained between the free end of each carbon nanotube and the negative electrode, and each negative electrode is connected to the negative electrode of the power supply after being connected in parallel; the fixed end of each carbon nanotube arranged in a row is fixed on the positive electrode, and each positive electrode is mutually connected After parallel connection, the positive pole of the power supply is connected, and the free end of each carbon nanotube maintains a nanoscale gap with a negative electrode plate, and the negative electrode is connected to the negative pole of the power supply. By applying a voltage between the two electrodes, a strong electric field is generated in the gap between the carbon nanotubes and the electrodes, causing the carbon nanotubes to generate electricity in the THz range due to the electrical elongation and the resulting changes in tunneling current and electric field strength. Control electromechanical oscillation. The frequency of the oscillator is mainly determined by the length of the carbon nanotubes, which can realize oscillations between hundreds of GHz and tens of THz. It is expected to be used in THz signal technology, nano-electromechanical systems and other fields.

Description of drawings

Figure 1 is a schematic diagram of a UHF nano-oscillator. The label names are: 1. Carbon nanotube, 2. Positive electrode, 3. Negative electrode.

Figure 2 is a schematic diagram of the working principle of the ultra-high frequency nano-oscillator.

Fig. 3 is a front view of the array ultrahigh frequency nano oscillator.

Fig. 4 is a top view of an arrayed ultrahigh frequency nano-oscillator.

Detailed ways

Fig. 1 is a schematic diagram of the ultra-high frequency nano-oscillator of the present invention, wherein carbon nanotubes 1 can be directly grown on the positive electrode 2, or connected to the positive electrode 2 by physical or chemical methods. The control of the distance between the free end of the carbon nanotube 1 and the electrode 3 is a key link, which can be realized by high-precision displacement control, such as the atomic force microscope probe technology, and can also be controlled by chemical template positioning and processing methods. A simple circuit is required between the positive electrode 2 and the negative electrode 3 to provide an operating voltage.

Figure 2 is a schematic diagram of the working principle of the ultra-high frequency nano-oscillator. (a) When the carbon nanotube 1 is not applied with an external electric field, there is no deformation and no tunneling current; (b) when the carbon nanotube 1 is applied with an external electric field, there is no deformation and no tunneling current; (c) due to Under the action of an external electric field, the end of the carbon nanotube 1 produces an electric field enhancement effect, and a strong electric field is generated between it and the negative electrode 3. A strong tunneling current is generated in the close-to-nano spacing; (d) when the carbon nanotube 1 leads to the maximum electrical elongation under the external electric field, the current reaches the maximum and the voltage between the gaps becomes the minimum; (e) due to the gap The electric field force in between drops sharply, the charges accumulated in the carbon nanotubes are released, and the carbon nanotubes 1 will rebound, and the tunneling current generated in the nanometer distance that is in close contact with the negative electrode 3 makes the current continue to maintain a small amount; (f) The carbon nanotube 1 retracts to the original position, no tunneling current is generated, and the current becomes the minimum. In the future, under the action of strain force, electric field force, and charge injection, the ultra-high frequency nano-oscillator needs to experience (b)--(c)--(d)---(e)--(f)--( The cyclic process of b) produces continuous controllable oscillation of the ultra-high frequency motor.

Fig. 3 and Fig. 4 are schematic diagrams of array ultrahigh frequency nano-oscillators. This array type ultra-high frequency nano oscillator is to arrange carbon nanotubes in a determinant structure, as shown in Figure 3, arrange carbon nanotubes in rows, and the fixed end of each carbon nanotube is fixed on the same positive electrode On the board, the positive electrode plate is connected to the positive electrode of the power supply, and the free ends of each carbon nanotube are connected to the negative electrode respectively; as shown in Figure 4, the carbon nanotubes are arranged in columns and rows as shown in Figure 3 to form an array structure , the fixed end of each carbon nanotube in a row is respectively fixed on a positive electrode, all the positive electrodes are connected in parallel to each other and then connected to the positive electrode of the power supply, and the free end of each carbon nanotube maintains a nanoscale gap with a negative electrode plate , this negative plate is connected to the negative pole of the power supply. The design of the array ultrahigh frequency nano oscillator is to realize the output signal amplification of the ultra high frequency nano oscillator. Achieving high power output can be used in THz signal technology, nano-electromechanical systems and other fields.

Claims (3)

1. An ultra-high frequency nano-oscillator, characterized in that, comprises carbon nanotubes (1), positive electrode (2), negative electrode (3) and power supply. Wherein the fixed end of the carbon nanotube (1) is connected to the positive electrode (2), there is a nanoscale gap between the free end of the carbon nanotube (1) and the negative electrode (3), and the positive pole of the power supply is connected to the positive electrode (2) , the negative pole of the power supply is connected to the negative electrode (3). 2. ultra-high frequency nano oscillator according to claim 1, is characterized in that, the nanoscale gap between carbon nanotube (1) free end and negative electrode (3) is within 10% of carbon nanotube length, Its magnitude is related to frequency requirements and designed voltage. 3. An array type ultra-high frequency nano-oscillator is characterized in that carbon nanotubes are arranged into a determinant array structure, and the fixed ends of each carbon nanotubes arranged in rows are all fixed on the same positive electrode plate , connected to the positive pole of the power supply, a nanoscale gap is maintained between the free end of each carbon nanotube and the negative electrode, and each negative electrode is connected to the negative pole of the power supply after being connected in parallel; the fixed end of each carbon nanotube arranged in a row is fixed on the positive electrode , each positive electrode is connected in parallel to each other and then connected to the positive electrode of the power supply, the free end of each carbon nanotube maintains a nanoscale gap with a negative electrode plate, and the negative electrode is connected to the negative electrode of the power supply.

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